Now the cargo stuff is pretty straightforward however crew is another issue since it requires apparently a crew escape mechanism which SpaceX say will require up to 3 years for development. Lifeboat doesn't require crew escape so less development time required for this option.

Came across an interesting bit of info' yesterday when I was trolling through YouTube about crew escape. Seems SpaceX is doing this one differently as well and it'll be interesting to see if they can pull it off:

Thanks for the video link. I am intrigued. It would be great to hear more details. The orbital maneuvering system is hypergolic. How does that scale from 90lbf draco thrusters to whatever force is necessary to out-race the first stage just before Main engine cutoff?

They will definitely need beefed up plumbing. On the whole, I like it. Escape towers always seemed like one more potential problem to me.

Don't think they're going to be using the thrusters, it would have to be much more powerful but still liquid fuel system. Wonder if they're planning on integrating with the second stage main engine.

Seems to me that this might be possible since if you needed the abort, then wouldn't need the engine for anything else but if you didn't abort then you'd have your normal second stage engine.

Having another powerful engine plus possibly additional fuel, etc to lug to orbit on the chance that you might need it seems a waste. Also doesn't seem like the sort of path SpaceX would likely go down. They're into efficiency and reliability not wasted effort.

Last I heard on the configuration was:1. New LAS motor will use the hypogolic fuel load used by the Draco thrusters.2. Still planning for land landings couple of senerios: legs, crushable shockers, bags, motor/s - seems like the design still has some way to go before finalised.

@ beancounterPlease don't take this as an offense, but I just noticed that you have been speculating about something that doesn't make much sense:

beancounter wrote:

Wonder if they're planning on integrating with the second stage main engine.

With that approach, how could you abort if there is a problem with the second stage? In that interview from March, Musk explicitly stated that they are aiming at abort capability all the way up to orbit, so the LAS has to be independent of the second stage.

And with regard to your most recent post:

beancounter wrote:

Last I heard on the configuration was:1. New LAS motor will use the hypogolic fuel load used by the Draco thrusters.2. Still planning for land landings couple of senerios: legs, crushable shockers, bags, motor/s - seems like the design still has some way to go before finalised.

Cheers

That the LAS motor(s) will use the fuel load for orbital maneuvering is exactly what Musk has said back in March - and it makes perfect sense since you never really need that fuel for both applications.

But to say something more positive as well: Thanks for telling us about their plans for land landings. I didn't even know that they were working on that at all!

@ beancounterPlease don't take this as an offense, but I just noticed that you have been speculating about something that doesn't make much sense:

beancounter wrote:

Wonder if they're planning on integrating with the second stage main engine.

With that approach, how could you abort if there is a problem with the second stage? In that interview from March, Musk explicitly stated that they are aiming at abort capability all the way up to orbit, so the LAS has to be independent of the second stage.

And with regard to your most recent post:

beancounter wrote:

Last I heard on the configuration was:1. New LAS motor will use the hypogolic fuel load used by the Draco thrusters.2. Still planning for land landings couple of senerios: legs, crushable shockers, bags, motor/s - seems like the design still has some way to go before finalised.

Cheers

That the LAS motor(s) will use the fuel load for orbital maneuvering is exactly what Musk has said back in March - and it makes perfect sense since you never really need that fuel for both applications.

But to say something more positive as well: Thanks for telling us about their plans for land landings. I didn't even know that they were working on that at all!

Yeh didn't think that one through so point to you Macus. Just trying to get a bit of life going in the thread

Once the ability to accurately control reentry is proven, SpaceX plans to add deployable landing gear and use thrusters to safely land Dragon on land.

That's interesting

Agreed. Seems to me that this is not the sort of thing you'd just add. Therefore SpaceX seems to have had this in their 'plan' from the beginning along with lots of other things I guess. And this would make sense given Elon's vision of extending life to other planets. Be interesting to know how deep this runs in the culture of the company.

Very interesting an escape system that uses the same fuel & tanks as the OMS. Presumably this will also provide a extra redundant propulsion system that would in a pinch could be used for the de-orbit burn?